Effect of liquid-phase properties on ultrasound intensity and cavitational activity

Majumdar, Sukti; Kumar, Parveen; Pandit, Aniruddha B.

doi:10.1016/s1350-4177(98)00019-4

Cited by 51 publications

(29 citation statements)

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“…Due to geometrical spreading, the acoustic pressure generated by an acoustic transducer drops with increasing distance from the transducer surface [36]. Studies at EKOS, consistent with other studies, have shown that USenhanced thrombolysis is dependent on acoustic pressure generated by transducer [37, 38].…”

Section: Discussionmentioning

confidence: 69%

Potentiating intra-arterial sonothrombolysis for acute ischemic stroke by the addition of the ultrasound contrast agents (Optison™ & SonoVue®)

Soltani

Singhal

Obtera

et al. 2010

J Thromb Thrombolysis

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Transcranial ultrasound in combination with intravenously administered ultrasound contrast agents (UCA) in the presence or absence of recombinant tissue plasminogen activator (rt-PA) has been widely evaluated as a new modality for treatment of ischemic stroke. Despite the successful demonstration of accelerated clot lysis there are inherent limitations associated with this modality such as inconsistency in temporal window thickness and/or potential serious cardiopulmonary reactions to intravenous administration of UCA that prevent broad application to ischemic stroke populations. As a complementary modality, we evaluated potential lysis enhancement by intraarterial ultrasound with concurrent intra-clot delivery of UCA and rt-PA. To this end, clots were formed with average pore diameter similar to clinically retracted clots by adjusting the thrombin concentration. Physical characteristic and retention of UCA after delivery through the catheter as a function of clinically relevant flow rates of 6, 12, 18 ml/h were determined using a microscopic method. The ability of the UCA employed in this study, Optison and SonoVue, to penetrate into the clot was verified using ultrasound B-mode imaging. Clot lysis as a function of rt-PA concentration, 0.009 through 0.5 mg/ml, in the presence and absence of UCA diluted to 1:10, 1:100, and 1:200 v/v at two Peak rarefaction acoustic pressures of 1.3 and 2.1 MPa were evaluated using a weighing method. The study results suggest the addition of only 0.02 ml of 1:100 diluted UCA to rt-PA of 0.009, 0.05, 0.3, and 0.5 mg/ml can enhance the lysis rate by 3.9, 2.6, 1.9 and 1.8 fold in the presence of peak rarefaction acoustic pressure of 1.3 MPa and by 5.1,

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Section: Discussionmentioning

confidence: 69%

Potentiating intra-arterial sonothrombolysis for acute ischemic stroke by the addition of the ultrasound contrast agents (Optison™ & SonoVue®)

Soltani

Singhal

Obtera

et al. 2010

J Thromb Thrombolysis

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“…Interestingly, the dependence of cavitation threshold on viscosity demonstrated in the present work ( Figure 5) has confirmed the results of the previous theoretical study [11], which predicts that the cavitation threshold increases with growing viscosity. On the other hand, it has been shown [12] that attenuation of the ultrasound is dependent on viscosity. However, the attenuation of the effects of ultrasound in the EECA is insignificant considering distance of ultrasonic transducer from the source of ultrasound because EECA is much less viscous than oils used in the previous study [12].…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, it has been shown [12] that attenuation of the ultrasound is dependent on viscosity. However, the attenuation of the effects of ultrasound in the EECA is insignificant considering distance of ultrasonic transducer from the source of ultrasound because EECA is much less viscous than oils used in the previous study [12]. This method could be robust if an appropriate algorithm for the evaluation of increasing noise-voltage is developed.…”

Section: Resultsmentioning

confidence: 99%

Detection of ultrasonic cavitation based on low-frequency analysis of acoustic signal

Brabec

Mornstein

2007

Open Life Sciences

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Abstract:The acoustic cavitation phenomenon constitutes a potential hazard in ultrasound diagnostics and therapy so that early and effective detection of cavitation is of great interest. However, cavitation might even bring a higher risk especially when an echocontrast agent based on microbubbles is used. The major goal of the present work was to develop a cavitation detection method based on increased level of cavitation noise in the range of low frequencies (about 1 Hz). This method was applied in vitro using a model of body fluid containing a model echocontrast agent, such as 5% solution of lyophilized egg albumin, which was sonicated by ultrasound disintegrator. Ultrasound signal evokes cavitation in microbubble suspension accompanied by a certain level of cavitation acoustic noise. The level of noise voltage increased in the frequency range of 0.1 to 2 Hz in the presence of cavitation. Hence, this method makes it possible to determine the value of cavitation threshold. In addition, we examined how the cavitation threshold is affected by temperature and viscosity. It was found that the cavitation threshold decreased with growing temperature while it increased with growing viscosity.

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“…Only a small fraction of the total liquid volume in the immediate vicinity of the ultrasound source experiments the effects of cavitation. The intensity of ultrasound is continuously attenuated by the molecules present in the liquid due to various cohesive forces acting on the liquid 16 . The ultrasonic intensity profile in the baths depends entirely on the design and location of the transducers.…”

Section: Introductionmentioning

confidence: 99%

“…A great variety of techniques for the measurement of ultrasonic or cavitation intensity has been listed in the literature 18 , such as chemical reactions 19 , elastic sphere radiometry 20 , aluminium foil erosion 21 , calorimetric and optical methods 16,19,22 , thermoprobes 21 and others 18,23 .…”

Section: Introductionmentioning

confidence: 99%

Use of ultrasonic baths for analytical applications: a new approach for optimisation conditions

Nascentes

Korn

Sousa

et al. 2001

J. Braz. Chem. Soc.

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Com o emprego de um método simples e rápido, são propostas algumas condições de otimização para a obtenção de máxima intensidade de cavitação em banhos de ultra-som. Os parâmetros estudados foram: volume de água dentro do banho, temperatura, concentração de detergente, posição vertical e horizontal dos tubos no banho, número de tubos dentro do banho, tempo de sonicação e substituição da água do banho. Os resultados obtidos para os banhos de ultra-som estudados (Neytech e Cole-Parmer) permitiram estabelecer as seguintes condições para máxima intensidade de cavitação: 1 L de água à temperatura ambiente; 0,2 % (v/v) de detergente; posição central e ao fundo do banho. Somente 1 tubo deve ser usado por vez dentro do banho durante a aplicação do ultra-som. A intensidade de cavitação foi linear com o tempo de sonicação até 10 minutos e a substituição de água durante a sonicação melhorou a reprodutibilidade. Esse sistema de troca contínua de água permite a sonicação de até 6 amostras consecutivamente sem mudanças no volume total de água.Optimisation conditions for obtaining maximum cavitation intensity in ultrasonic baths are proposed using a simple and fast method. Parameters such as water volume, temperature, detergent concentration, horizontal and vertical positions, number of tubes in the bath, sonication time and bath water substitution were studied. The results obtained for both baths studied (Neytech and Cole-Parmer) lead to the following conditions for maximum cavitation intensity: 1 L of water at room temperature, 0.2 % (v/v) of detergent, central position on the bottom of the tank. Only one tube at a time should be used inside the bath during the ultrasound application. The cavitation intensity was linear with the sonication time up to 10 minutes and the water substitution during the sonication improved reproducibility. This system using continuous water change makes possible the sonication of 6 consecutive samples, without changes in the water volume.

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Effect of liquid-phase properties on ultrasound intensity and cavitational activity

Cited by 51 publications

References 1 publication

Potentiating intra-arterial sonothrombolysis for acute ischemic stroke by the addition of the ultrasound contrast agents (Optison™ & SonoVue®)

Potentiating intra-arterial sonothrombolysis for acute ischemic stroke by the addition of the ultrasound contrast agents (Optison™ & SonoVue®)

Detection of ultrasonic cavitation based on low-frequency analysis of acoustic signal

Use of ultrasonic baths for analytical applications: a new approach for optimisation conditions

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